Twin-cylinder two-stroke internal-combustion engine



Dec. ,4 1923. 1,476,351

D. STANGER TWIN CYLINDER TWOSTRCKE INTERNAL COMBUSTION ENGINE Filed July12, 1920 I 4 Sheets-Sheet 1 D. STANGER TWIN CYLINDER TWO-STROKE INTERNALcomausnou ENGINE Dec. 4 1923.

Filed July 12, 1920 4 Sheets-Sheet 2 Dec. 4 1923. 1,476,351

D. STANGER TWIN CYLINDER TWO-STROKE INTERNAL COMBUSTION ENGINE FiledJuly 12, 1920 4 Sheets-Sheet 5 L I e r ,3 w 7&2

l 7; 'TJ

l JMMD @E a m J Dec. 4 1923. 1,476,351

D. STANGER TWIN CYLINDER TWO-STROKE INTERNAL COMBUSTION ENGINE FiledJuly 12, 1920, 4 Sheets-Sheet 4 Patented Dec. 4, 1923.

UNITED STATES- DAVID STANGER, OF STROUD, ENGLAND.

TWIN-CYLINDER TWO-STROKE INTERNAL COMBUSTION ENGINE.

Application filed July 12,

T0 (1Z6 1127mm it may cance /'11 Be it known that T, Davin Samoan, asubject of the King of Great Britain and Ireland, and a resident ofStroud, county of Gloucester, England, have invented a certain new anduseful Improvement in Twin- Cylinder Two-Stroke Internal-CombustionEngines, of which the following is a speciiication.

This invention relates to two-stroke internal combustion engines of twocylinders with independent firing in each cylinder, resulting in twopower strokes per revolution, and in which the crank case is dividedinto pressure compartments. The said invention contemplates anarrangement of the crank case for a V-shaped disposition of thecylinders by means of which the outward configuration of most V-typetwin-cylinder engines is attained and is therefore capable, among otheradvantages, of adaptation to standard motor cycle frames. I

The objects of the invention are, to permit the use of a short andpreferably solid crank shaft; to enable the centres of pressure of thepiston, the axis of the connecting rod, and the middle of the crank tobe in the same straight line, to reduce the overall dimen sions of theengine to a minimum and to ensure a minimum lateral displacement of thecylinders, thereby avoiding undue vibration and any necessity ofbalancing the crank shaft by counterweights; to reduce the number ofparts to a minimum and'ensure rapidity, compactness and reliability. Afurther object of the invention is to prevent leakage between thecompression chambers and between the compression chambers andatmosphere.

The invention consists for the main part in the provision in an engineof the type described of a crank case consisting of a casting in twoparts, the two parts when together comprising two crank compressioncompartments side by side and separated by a common vertical wall orpartition which is pierced for the passage of the crank shaft. The crankshaft takes its bearings in the external walls of the crank case oneither side. The two parts of the casting are divided in the horizontalplane containing the axis of the crank shaft and its bearings, so that,when the two parts are separated, the crank shaft, which for that reasonmay be made solid, may be readily removed. The upper part of the castingcarries the cylinder plat 192d. set-1m No. 395,758.

forms, arranged at a suitable angle on its upper surface, and the livegas ports, the gas port for each cylinder preferably passing over thepartition wall across the middle line of the casting and coming upbehind the otter cylinder platform so as to economize space. It alsobears lugs or other suitable means of attaching the casing to the frame.The lower part contains the lower portions of the two crank compressionchambers, the dividing partition, and the lower halves of the crankshaft housings. The two parts of the casings are united, when assembled,preferably by nuts and bolts.

The invention further consists of an improved of crank shaftbearing-bushes to minimize loss of compression in the shape of solidbearing bushes of T-section disposed in corresponding recesses in thecasting with washers as hereinafter more particularly described.

In order that the said invention may be readily understood, reference isdirected to the following description and accompanying sheets ofdrawings wherein one practical embodiment with cylinders set at or aboutan angle of 45 degrees is illustrated in more or less diagrammaticmanner, and in said drawings:

Figure 1 is a plan, cylinders removed.

Figure 2 is a part sectional side elevation.

Figure 3 is a section through 00, m-Figure 2; and,

Figure 4 is a side view of Figures 1 and 2, cylinders removed.

Like letters of reference indicate corresponding parts in theseveralviews.

The crank case is indicated as a whole by a, and has a staggeredarrangement of platforms Z) and c for the cylinders b and 0 Thus, thelatter may be set, nearly or subst-antially in the same plane, as willbe more clearly seen from Figures 1, 3 and 4c. In Figures 1 and 3, thecrank case dividing wall (Z in seen, and it is arranged to allow thetransfer port 6 to lead from the crank case chamber to cylinder 5 behindplatform 0, and the transfer port f to lead from the crank case tocylinder 0 behind platform 5, thereby minimizing the amount of staggerof platforms 0, b, which determine the stagger of cylinders 0 and 72respectively.

In Figures 2, the connecting rods 0 and 79 with roller bearings 0 and pare shown.

In conjunction with the foregoing arrangement of crank case, it ispreferred to em ploy the gas-tight means of retaining the crank casecompression illustrated, but the said crank case with the attendantstaggering of cylinders, the arrangement of transfer passages and otherdetails is not neces sarily confined to this means. The said gas-tightmeans consists of T-section solid bushes and 7: which are fitted inrecesses bored in the crank case, the centre bush i being a split oneheld by means of a special split wire ring 2' Figure 3 also shows howthe driving load is taken on the crank shaft 2' by two double-row ballbearings m and 11, with fibre Wasl'ier's n and n which minimize the lossof crank case compression. The bushes 2', j, and 7a retain compressionfor very long periods and require very little attention except for anoccasional turn of the grease caps i 3' and Z2 about every five hundredmiles. The bushes i, and is are furnished with grease grooves whichallow the grease to pass through the channels Q,

r and s to the crank shaft Z. Figure shows also how the constructionallows the employment of a very short crank, practically eliminating allWhip, a very important feature. In, Figure 4 are shown the grease caps ij and is, and also the stagger and sloping platforms 6 and chereinbefore referred to are clearly seen.

Four of the eight bolts ((4 a, a and a which hold the two halves of thecrank case" (2 together are shown.

It is to be understood that the invention is capable of modification onthe broad lines indicated in the foregoing description without departingfrom the spirit of the invention.

I claim In an internal combustion engine of the class described, a crankshaft, a crank case consisting of two parts adapted to be joined at theline of the crank shaft and forming two compression compartments, acommon vertical partition separating the compartments and pierced forthe passage of the crank shaft, cylinder platforms carried by the upperpart, and said upper part having a gas port for each cylinder, said portbeing led over the partition and across the middle line of the casingand up behind the other cylinder.

In testimony whereof I have aflixed my signature hereto this th day ofJune, 1920.

DAVID STANGER.

